Seven people -- including high school students -- have been injured in a school bus crash north of Auckland

Emergency services were called to the collision between a bus and car, near the intersection of State Highways 1 and 12 on the Brynderwyn Hills.

St John treated seven patients at the scene -- and transported five to a Whangarei Hospital in a moderate condition.

It's understood 18 people left the scene before emergency services arrived and were taken to Otamatea High School, in Maungaturoto.

Otamatea High School says the school and health services are supporting students involved in the crash.